A process known generally by the term “electroplating” is a well known technique for plating a metal onto a surface of an article.
Typically the process is carried out in a cell containing an anode, a cathode which is formed by the article to be plated, and also a liquid electrolyte. The electrolyte contains ions of the metal to be plated. A potential difference is applied across the electrodes driving the deposition of metal ions on the cathode. This process has been used for a long time to plate metals such as copper (Cu), tin (Sn), zinc (Zn) and gold (Au) onto metallic surfaces. Other materials that can be plated out on an article by conventional electroplating techniques include: Cr, Ni, Fe, Co, Cd, Pb, Ag, In and Pt. The purpose for coating a metal with such a plating varies. Sometimes metals may be coated to reduce their susceptibility to corrosion. Other times they may be coated with e.g. gold to increase their aesthetic appeal and value.
However while there are a large number of materials that can be deposited by electroplating techniques there are many other materials, e.g. so-called advanced materials, that are not able to be deposited by conventional electrode plating techniques. This is because the electrode chemical series of the metal simply does not permit deposition with the voltages that would ordinarily be used.
Clearly it would be advantageous if a technique could be devised for depositing or plating these advanced materials on the surface of an article. This would open up a plethora of new options in this exciting field. It would open up numerous new possibilities in terms of the type of materials that could be deposited and flowing from this would be a multitude of new applications for the deposition of thin films.
Currently the deposition of advanced materials is accomplished by means of ion vapour deposition or sputtering techniques. For all practical purposes these are required to be carried out in a vacuum chamber. These processes do have some limitations. Firstly fairly sophisticated vacuum equipment is required to carry out the process. Secondly some sputtering techniques are directional and may therefore be primarily suitable for coating one surface of articles. Such devices are not designed to circumferentially coat surfaces and may not be able to coat surfaces having a widely varying three dimensional configuration. Thus the number and size of the articles can be limited by the size of the vacuum chamber. Further the product turnaround time is long. Temperatures are high and as a result delicate and heat sensitive materials cannot be coated by this process.
The current application is squarely focused on this challenge.